The long-term objective of this project is to conclude a longitudinal study of infants exposed to methadone in-utero in comparison to control subjects, examining the infants' short- and long-term physical, behavioral, and cognitive outcomes. All study infants are born to mothers in the Family Center Program which provides comprehensive obstetrical, medical, psychosocial, and addictive care. Control subjects are born to mothers who are provided similar obstetrical care within the prenatal clinics of the same hospital. The course and severity of infant withdrawal and the most appropriate pharmacologic treatment will be evaluated and related to cognitive assessments at six months of age. Although adequate prenatal care and appropriate medical treatment of neonatal abstinence markedly lowers the risk of medical complications for the infant, long-term assessment of pertinent developmental variables will allow for the investigation of the relationship between abstinence and outcome during infancy and early childhood. Neonatal abstinence symptomatology is precisely measured by an abstinence scoring system. Effectiveness of pharmacologic treatment is assessed by the amount of time needed to bring the symptoms under control. Infants are randomly assigned to a particular drug of treatment and all will be compared neurologically, as well as cognitively with the Bayley Scales of Infant Development. For purposes of the longitudinal investigation, all treatment groups will be combined and the repeated cognitive neurological, physical, and behavioral evaluations of drug exposed and control children up to five years of age will address long-term development. The environmental issues of development will also be addressed by assessing the amount of stimulation provided at home and maternal knowledge of parenting. The psychological and social issues of maternal depression, low self-esteem, and poor social support will be addressed by obtaining repeated measures of these variables for all Family Center patients and the comparison population.